SAT语法题...谢谢1.（OG TEST9 section3.10）In Germany, foresters dis

SAT语法题...谢谢
1.（OG TEST9 section3.10）
In Germany, foresters discivered that trees killed by acid rain had begun to die four years (earlier, even though the trees had shown no signs of disease then.)
A
B earlier, but not showing any signs of disease then
C earlier, no outward sighs of disease had been shown then in the trees, however
D earlier without any signs of disease shown then
E earlier, not then having shown any signs of disease, however
这个题答案选A,想知道为什么不能选D
2.(0710 section10.5)
(Because of pleading in vain for improve maintenance services, the tenants refused) to pay rent until the landlord agreed to make the much-needed repairs.
A
B Having pleaded in vain for improved maintenance services, the tenants refused
答案是B 感觉A更好一些 还有因果关系啊..
3.(Princeton test8 section10 8)
Disneyland in California (was the first Disney theme park, but today there are also) Disney World in Florida and Euro Disney outside Paris.
A
B is the first Disney theme park, but today there is also